#include <cstdio>
#include <fstream>
#include <iomanip>
#define IN "secv3.in"
#define OUT "secv3.out"
#define rint register int

const int MAX = 30010;
using namespace std;
double timp[MAX],cost[MAX],st[MAX],sc[MAX];
ofstream fout (OUT);
int main()
{
    rint n,u,l;
    double maxim=0;
    freopen(IN,"r",stdin);
    //freopen(OUT,"w",stdout);
    scanf("%d%d%d",&n,&u,&l);
    for(rint i=1;i<=n;scanf("%lf",cost+i),++i);
    for(rint i=1;i<=n;scanf("%lf",timp+i),++i);
    for(rint i=1;i<=n;sc[i]=sc[i-1]+cost[i],++i);
    for(rint i=1;i<=n;st[i]=st[i-1]+timp[i],++i);
    for(rint i=1;i<=n-u+1;++i)
        for(rint j=i+u-1;j<=n and j<=i+l-1 and j<=i+u+1000;++j)
            if(sc[j]-sc[i-1]>maxim*(st[j]-st[i-1]))
                maxim=(sc[j]-sc[i-1])/(st[j]-st[i-1]);
    //printf("%.2lf",maxim);
    fout<<fixed<<setprecision(2)<<maxim<<'\n';
    return 0;
}